1. Field of Use
This invention relates generally to a transmission system including a solenoid-operated reversible multispeed transmission, such as is used in vehicles, an electronic control circuit for operating the transmission solenoids, and a manually operated control device, including a control lever and electric switches, for operating the electronic control circuit to effect shifting of the transmission.
2. Description of the Prior Art
Transmission systems of said aforesaid character and others are known and shown in U.S. Pat. Nos. 4,015,488 of Apr. 5, 1977 entitled "Digital Electronic Controller For Power Transmission"; 3,613,480 of Oct. 19, 1971 entitled "Power Transmission Having Downshift Inhibitor"; 4,275,607 of June 30, 1981 entitled "Power Shaft Transmission Having Power Take-Off Shaft and Fluid Control Means Therefor"; 4,090,414 of May 23, 1978 entitled "Transmission Control System For Shuttle Type Vehicles"; 4,067,423 of Jan. 10, 1978 entitled "Control System for Rotary Drill"; and 3,805,640 of Apr. 23, 1974, entitled "Electronically Controlled Power Transmission", all of which patents have been assigned to an assignee common with the present invention. In some of such prior art systems, the manually operated control device typically comprises a housing from which a manually operable control lever extends and within which are located switches which are actuated as the control lever is moved from one position to another. Usually, the control lever is movable from a neutral position either in the forward or reverse direction to any one of several detented positions corresponding to a selected shift range or speed. Such an arrangement is sometimes time-consuming to use and, when direction reversal is required, it is necessary to downshift mechanically and electrically through all intervening shift ranges.